Leak from Sink? Common Causes, Quick Fixes & When to Call an Emergency Plumber

A leak from sink might look like a small issue at first, but it can quickly turn into serious water damage if ignored. From dripping pipes under the sink to water pooling around the base, sink leaks are one of the most common plumbing emergencies in Sydney homes. In this guide, we’ll explain the most common causes of sink leaks, what you can safely do right away, and when it’s time to call an emergency plumber to prevent costly damage.

Why a Leaking Sink Is a Bigger Problem Than You Think

Even a slow leak can:

• Damage cabinets and flooring
• Cause mould and mildew growth
• Increase water bills
• Lead to pipe corrosion or burst pipes

In apartments or multi-storey homes, sink leaks can even affect neighbouring properties. Acting fast is key.

Common Causes of a Leak from Sink

Understanding where the leak is coming from helps determine whether it’s a quick fix or an emergency.

1. Loose or Worn Pipe Connections

Pipes under the sink are joined with fittings that can loosen over time due to:

• Regular vibration
• Temperature changes
• Poor installation

This often causes dripping directly under the sink.

2. Damaged or Perished Washers

Rubber washers inside taps and valves wear out with use. When this happens, water escapes even when the tap is turned off.

Signs include:

• Constant dripping
• Difficulty fully shutting off the tap
  

3. Cracked or Corroded Pipes

Older metal pipes can corrode, while plastic pipes may crack due to pressure or impact. These leaks usually worsen quickly and should be treated as urgent.

4. Faulty Sink Drain or Trap

The U-bend (trap) under the sink can develop leaks due to:

• Blockages
• Loose fittings
• Cracks

Water often leaks when the sink is in use.

5. Sealant Failure Around the Sink

If water appears around the edges of the sink, the silicone seal may have deteriorated, allowing water to seep into benchtops and cabinets.

What to Do Immediately If Your Sink Is Leaking

Before calling a plumber, there are a few safe steps you can take to minimise damage.

Step 1: Turn Off the Water Supply

Locate the isolation valve under the sink and turn it clockwise.
If you can’t find it, turn off the main water supply.

Step 2: Contain the Leak

Use:

• A bucket or bowl under the leak
• Towels to absorb excess water

This helps prevent further damage while waiting for repairs.

Step 3: Check for Obvious Loose Connections

If the leak is minor and visible, gently tighten fittings by hand. Avoid overtightening, as this can make the problem worse.

Step 4: Avoid Using the Sink

Continuing to use a leaking sink increases pressure and damage.

DIY Fix or Emergency Plumber: How to Decide?

Some minor issues can be handled temporarily, but many sink leaks require professional attention.

You MAY attempt a temporary fix if:

• The leak is slow
• The source is clearly visible
• There is no water damage yet

Call an emergency plumber immediately if:

• Water is pooling rapidly
• Pipes are cracked or spraying water
• You can’t stop the leak
• Water is damaging cabinets, walls, or floors
• The leak occurs outside normal hours

Emergency plumbers are equipped to stop leaks fast.

Why You Shouldn’t Ignore a Sink Leak

Delaying repairs can lead to:

• Structural damage
• Electrical hazards if water reaches wiring
• Pest infestations due to damp areas
• Insurance claim complications

What starts as a simple leak can turn into a major repair job.

How an Emergency Plumber Fixes a Sink Leak

When you call an emergency plumber, they typically:

• Identify the exact source of the leak
• Replace damaged pipes, washers, or seals
• Test water pressure and drainage
• Ensure the issue won’t recur

Professional repairs are faster, safer, and long-lasting.

Preventing Future Sink Leaks

While not all leaks are avoidable, you can reduce risk by:

• Checking under-sink pipes every few months
• Avoiding chemical drain cleaners
• Fixing slow drips early
• Replacing old plumbing components proactively

Regular maintenance saves money and stress.

A leak from the sink is not something to ignore. While some leaks start small, they often signal deeper plumbing issues. Acting quickly protects your home, your wallet, and your peace of mind.

If you’re dealing with an active leak and need immediate help, it’s always safer to contact a licensed emergency plumber who can fix the issue properly the first time.